Causation Ontology?

Hi,
I posted the questions below on dbpedia and jena lists but maybe it is more appropriate to ask here. Let me add that I would like to know if there is a sorts of unified way to represent causation between these different ontologies and data sets and if, as it seems, there is not, how do I myself create one? Any pointers?
Thanks much!

Marv

-------here is my original email----

Try the following SPARQL

select ?p ?o
where{
<http://dbpedia. org/resource/ The_Great_ Train_Wreck_ of_1856>
?p
?o
}

It will all the results the dbpedia has on that subject including:

?p = http://dbpedia. org/property/ cause
?o = human error

My question is why is the object a text string and not a URI?
If you lookup a disease, say Malaria, you can find its cause in the abstract as text but you cannot ask the question what causes Malaria and have it answered in dbpedia. I know these are difficult to extract but has anyone thought about doing this? Why is cause in the infobox of the train wreck but not in that of the disease? In Malaria the infobox points to a diseasedb reference (7728) can I follow that somehow to get the cause of malaria as a URI, and can that URI be used usefully with dbpedia?

Another question is that why cant I find the train wreck triple when I do the following:
grep The_Great_Train_ Wreck_of_ 1856 infobox_en.nt

In fact I cant find it (the train wreck cause triple) in any of the files (I am looking at files i downloaded 2 months ago and querying dbpedia live but has this cause property been added to the infobox this recently?)

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Received on Sunday, 16 November 2008 14:47:22 UTC